S T R E L I T Z I A 39 (2018) a b S T R E L I T Z I A 39 (2018) S T R E L I T Z I A 39 A TAXONOMIC REVISION OF Calobota (FABACEAE, CROTALARIEAE) James Stephen Boatwright, Patricia May Tilney and Ben-Erik van Wyk Pretoria 2018 S T R E L I T Z I A This series has replaced Memoirs of the Botanical Survey of South Africa and Annals of the Kirstenbosch Botanic Gardens, which the South African National Biodiversity Institute (SANBI) inherited from its predecessor organisations. The plant genus Strelitzia occurs naturally in the eastern parts of southern Africa. It comprises three arborescent species, known as wild bananas, and two acaulescent species, known as crane flowers or bird- of-paradise flowers. The logo of SANBI is partly based on the striking inflorescence ofStrelitzia reginae, a native of the Eastern Cape and KwaZulu-Natal that has become a garden favourite worldwide. It symbol- ises the commitment of SANBI to champion the exploration, conservation, sustainable use, appreciation and enjoyment of South Africa’s exceptionally rich biodiversity for all people. James Stephen Boatwright Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa; e-mail: [email protected]. Patricia May Tilney and Ben-Erik van Wyk Department of Botany and Plant Biotechnology, University of Johannesburg, P.O. Box 524, Auck- land Park 2006, Johannesburg, South Africa; e-mail: [email protected]; [email protected]. EDITOR: Alicia Grobler PROOFREADER: Yolande Steenkamp DESIGN & LAYOUT: Elizma Fouché Citing this publication: BOATWRIGHT, J.S., TILNEY, P.M. & VAN WYK, B-E. 2018. A taxonomic revision of Calobota (Fabaceae, Crotalarieae). Strelitzia 39. South African National Biodiversity Institute, Pretoria. ISBN: 978-1-928224-27-3 Obtainable from: SANBI Bookshop, Private Bag X101, Pretoria 0001, South Africa Tel.: +27 12 843 5000 E-mail: [email protected] Website: www.sanbi.org Printed by: Rand Data Forms (Pty) Ltd, P.O. Box 24194, Gezina, 0031 (Pretoria Office), tel. no.: +27 12 567 1564. Copyright © 2018 by South African National Biodiversity Institute (SANBI). All rights reserved. No part of this book may be reproduced in any form without written permission of the copyright owners. The views and opinions expressed do not necessarily reflect those of SANBI. The authors and publisher have made their best efforts to prepare this book, and make no representation or warranties of any kind with regard to the com- pleteness or accuracy of the contents herein. All images in this book have been reproduced with the knowledge and prior consent of the artists concerned and no responsibility is accepted by the publisher or printer for any infringe- ment of copyright or otherwise arising from the contents of this publication. Every effort has been made to ensure that the credits accurately comply with the information supplied by the authors. S T R E L I T Z I A 39 (2018) iii Contents Abstract ....................................................................... iv Acknowledgements ............................................................. v Introduction ................................................................... 1 Ethnobotany and chemistry. 3 Phylogenetic relationships ....................................................... 5 Horticultural potential .......................................................... 6 Materials and methods .......................................................... 7 Vegetative morphology and anatomy .............................................. 8 Reproductive morphology and anatomy ........................................... 13 Taxonomic treatment ........................................................... 19 Calobota Eckl. & Zeyh.. 19 Key to the species of Calobota . 21 1. Calobota acanthoclada (Dinter) Boatwr. & B.-E.van Wyk ........................ 22 2. Calobota angustifolia (E.Mey.) Boatwr. & B.-E.van Wyk ......................... 25 3. Calobota cinerea (E.Mey.) Boatwr. & B.-E.van Wyk ............................. 33 4. Calobota cuspidosa (Burch.) Boatwr. & B.-E.van Wyk. 37 5. Calobota cytisoides (Bergius) Eckl. & Zeyh.. 41 6. Calobota elongata (Thunb.) Boatwr. & B.-E.van Wyk ........................... 47 7. Calobota halenbergensis (Merxm. & A.Schreib.) Boatwr. & B.-E.van Wyk .......... 50 8. Calobota linearifolia (E.Mey.) Boatwr. & B.-E.van Wyk ......................... 54 9. Calobota lotononoides (Schltr.) Boatwr. & B.-E.van Wyk ......................... 58 10. Calobota namibensis Boatwr. & B.-E.van Wyk, sp. nov. ......................... 61 11. Calobota obovata (Schinz) Boatwr. & B.-E.van Wyk ............................ 64 12. Calobota psiloloba (E.Mey.) Boatwr. & B.-E.van Wyk ........................... 67 13. Calobota pungens (Thunb.) Boatwr. & B.-E.van Wyk ........................... 70 14. Calobota saharae (Coss. & Durieu) Boatwr. & B.-E.van Wyk . 74 15. Calobota sericea (Thunb.) Boatwr. & B.-E.van Wyk ............................ 77 16. Calobota spinescens (Harv.) Boatwr. & B.-E.van Wyk ........................... 82 References . 87 Index ......................................................................... 93 iv S T R E L I T Z I A 39 (2018) Abstract A taxonomic revision of the genus Calobota Thunb., Wiborgia and Wiborgiella. Calo­ Eckl. & Zeyh. (Fabaceae, Crotalarieae) is pre- bota differs from other closely related genera sented. Sixteen species are recognised in the in the tribe in the following combination of genus. Among these, Calobota namibensis characters: late bark formation, uni- or trifo- Boatwr. & B.-E.van Wyk is described as new liolate to simple, laminar leaves, hairy petals from southwestern Namibia. The anatomy of (C. cuspidosa (Burch.) Boatwr. & B.-E.van the leaves, stems and fruit walls was studied Wyk and C. psiloloba (E.Mey.) Boatwr. & and revealed important characters to distin- B.-E.van Wyk are exceptions), anther configu- guish Calobota from other genera of the tribe ration of 4+5+1 and laterally compressed or Crotalarieae. These include isobilateral leaves terete, usually pubescent pods. A detailed tax- (palisade parenchyma both adaxially and onomic study of the genus is presented here, abaxially) as opposed to dorsiventral leaves including a key to the species, descriptions, (e.g. in Wiborgia Thunb. and Wiborgiella typifications, distributions, phylogenetic rela- Boatwr. & B.-E.van Wyk), and thick-walled tionships and illustrations. fruit with gelatinous fibres in some species. The absence of mucilage cells in the epider- Keywords: Anatomy, Lebeckia, Lebeckia mis of the leaves is also an important distin- sect. Stiza, Fabaceae, Namibia, North Africa, guishing character for the genus with respect Papilionoideae, South Africa, Spartidium, to Aspalathus L., Lebeckia Thunb., Rafnia Wiborgiella. S T R E L I T Z I A 39 (2018) v Acknowledgements The authors thank the curators and staff of the listed herbaria for making their specimens avail- able for study or on loan. Financial support from the National Research Foundation of South Africa and the University of Johannesburg are gratefully acknowledged. We are grateful to Drs Sarah K. Gess and Friedrich W. Gess for supplying reprints of their publications on pollinators of the Crotalarieae. Michelle Smith is thanked for making the distribution maps. Collecting permits (permit numbers AAA005-00018-0028, 1362/2009) were provided by the conservation authorities of the Northern and Western Cape, and Namibia. The authors also wish to thank the anonymous reviewers for providing peer review reports on the manuscript, which resulted in several improvements to the text. Photographs: Front cover – Calobota angustifolia (typical form) by B.-E. van Wyk Top of back cover – Calobota sericea by J.S. Boatwright Bottom of back cover – Calobota sericea by J.S. Boatwright Inside the cover (collage) – Calobota cytisoides Page vi – Calobota pungens by B.-E van Wyk New species in this volume: Calobota namibensis Boatwr. & B.-E.van Wyk, sp. nov. (pg. 61) S T R E L I T Z I A 39 (2018) 1 Introduction The genus Calobota Eckl. & Zeyh. was re- Aspalathus L., Ezoloba B.-E.van Wyk & Boat- instated to accommodate the 16 species of wr., Rafnia Thunb. and Wiborgia Thunb. the Calobota group (Boatwright et al. 2009), (Boatwright et al. 2008, 2011). Most recently, previously included in the genus Lebeckia the genus Lotononis (DC.) Eckl. & Zeyh. was Thunb. As originally described by Ecklon & also divided into five genera, increasing the to- Zeyher (1836), the genus consisted of two tal number of genera in the Crotalarieae to 16 species, C. cytisoides (Berg.) Eckl. & Zeyh. and (Boatwright et al. 2011). C. pulchella (Andrews) Eckl. & Zeyh., which in actual fact represent the same taxon (now The species of Calobota occur throughout the C. cytisoides). Calobota was later reduced to a Greater Cape Region (Manning & Goldblatt section of an expanded concept of Lebeckia by 2012; Snijman 2013) and extend into Na- Bentham (1844) and several species included mibia. Some are important components of here by Bentham were previously placed in the Sperrgebiet, a species-rich area of south- other genera by Ecklon & Zeyher (1836). western Namibia (Burke & Mannheimer Harvey (1862) followed Bentham’s sectional 2004), while two other species, one described classification in the last revision of the genus herein and C. obovata (Schinz) Boatwr. & Lebeckia where 24 species were recognised. B.-E.van Wyk, are endemic to Namibia (Cra- In Boatwright et al. (2009) Calobota was ven & Vorster 2006). Calobota